Frictional transmission mechanism.



B. W. DAVENPORT.

FRIGTIONAL TRANSMISSION MECHANISM.

AFPLIOATION FILED NOV.29.1911,

1,066,472, Patented July 8. 1913.

State of Minnesota, have invented certain' tional transmission mechanism are jourillustrate the invention, like characters indi- -tary movements. "This sleeve 5 is provided UNITED OFFICE.

IBIRGE W. DAVENPORT, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR TO DISPATCH MOTOR CAR COMPANY, OF MINNEAI'OLIS, MIN NES OTA, A CORPORATION OF SOUTH DAKOTA.

FRICTIONAL TRANSMISSION MECHANISM.

Specification of Letters Patent.

Patented July 8,1913.

Application filed November 29, 1911. Serial No. 663,113.

To all whom it may concern:

Be it known that 1, Brass W. Davnnron'r, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and new anduseful Improvements in Frictional Transmission Mechanism; and I do hereby declarethe followin 'to bea full, clear, and exact description o theinvention, such as will enable others skilled in the art to which it appertains to make and use the same. a

My invention has for its object to. provide an extremely simple and highly efiiclent reversible variable speed frictional transmission mechanism, especiallyadapted for use on automobiles or'motor propelledvehicles, and to such ends, generallystated, the inven' tion consists of the novel devices and com binations of devices hereinafter described and-defined in the claims.

' In the accompanying drawings which cate like parts throughout theseveral views.

Referring to the drawings, Figure 1 is a plan view, showing the transmission mecha-' nism, some parts being broken away and: some'parts in horizontal section; and Fig. 2 is a side elevation of the parts shown in The various running parts of the fricnaled on ametal frame 1, which, as shown, is rectangular, and which is adapted to be rigidly or suitably secured to the framework of the automobile or motor propelled vehicle.

The numeral 2 indicates the engine crank shaft or a shaft driven from the engine crank shaft, and which, for thepurposes of this case, is treated as the driving' shaft. This shaft will extend longitudinally of the machine and is journaled in, suitable bearings 3 and 4, on the frame 1-. The driving shaft 2 is not directly journaled in the hearing 3', but is directly journaled in a bearing sleeve 5 mounted in the said bearing 3 with freedom for slight endwise and slight rowith a' projecting arm 6 that works in an oblique cam slot formed in the top of the bearing 3, so that by'oscillatory movements of the said arm '6, said sleeve 5' may be given a slight endwise .movement, thereby adapting the same to act as a thrust member for an important purpose which will presently appear.

Secured to the drivingshaft 2, just at the rear of the thrust sleeve 5 is a flat faced friction wheel or disk 8, the hub of which is subject tothe crowding force of the rear endof said sleeve Preferably, anti-friction devices, such as ball bearings 9, are interposed between the hub of the friction wheel 8, and the adjacent end of the thrust sleeve 5.

Keyed for rotation with the driving shaft 2, but mounted for sliding movements thereon, is a friction wheel 10, the hub 11 of which has a groove in which works anonrotary shipper ring 12, that is connectedto one end of an operating link 13. The fiatface of the friction wheel 8 affords a frictional working surface therefor, but the peripheral face of the wheel 10 affords the frictional working surface of the latter. To afford the proper peripheral frictional face to the wheel 10,it is provided with a rigidly secured inset peripheral friction ring 14, constructed of wood fiber or similar hard, tough, non-metallic material. The friction wheel 10 is interposed between and 006 crates with the flat frictional faces of a pair of friction wheels or disks 15 secured to the inner ends of a pair of axially alined driven shafts 16 journaled in suitable bearings 17, secured on the sides of the frame 1. These so-called driven shafts 16 are not directly journaled' in the said bearings 17 but are directly journalcd in thrust sleeves 18', which, in turn, are mounted in the said bearings 17 with freedom for slight endwise and slight rotary movements. Ball beanings 1.) are preferably interposed between the hubs of the friction wheels 15 and the inner ends of the thrust sleeves 18, and the said thrust sleeves .are provided with upwardly projecting arms 20 that work in oblique cam slots 21 formed in the tops of said bearings 17.

Secured to each shaft 16, as shown, directly to the hub of each friction disk 15, are friction wheels 22 provided in their-pe} ripherics with inset rigidly secured friction rings 23, of wood fiber or similar hard and tough non-metallic material. These friction rings 23 are adapted to run against the face of the friction wheel 8 to engage the same at diametrically opposite points and secured to the axis of the driving shaft 2.

The cam slots 21, in the tops of the bearings 17, it will be noted, are inclined in re ing bar which, in turn, is intermediately' pivoted to-an operating bar 26, which, in practice, may be connected to a. lever or other suitable actuating device. The arm 6 of the thrust hub 5 is shown as connected by a short link 27-fo a bell crank 28- pivoted on the frame 1 and adapted to be operated by a a rod 29 which, in turn, maybe actuated by a suitable lever or other device.

The link 13, which, as already noted, is connected to the shipper ring 12 for moving the friction wheel 10 toward and from the 'alined axes of the shafts 16, is shown as connected to'a lever 30, which, in turn, is

l 33, and the other'shaft 16 at its outer end.

shown as intermediately pivoted-t0 a projection 31 of the frame 1 and is connected to one end of an operating rod 32, which,

in turn, is adapted to be operated by a suitable lever or other device.

At one end, one of'the shafts 16 is shown as provided at its outer end with a sprocket is shown as provided with a spur gear that meshes with a. like spur gear 35-su1t- -ably journaled to the adjacent bearing 17 and provided with a sprocket 36: 'These sprockets 33 and 36 are adapted to drive sprocket chains which, in turn, will run over sprockets, not shown, 'onthe rear axle of the' automobile or motor propelled vehicle.

For the sake of brevity, the friction wheels which have peripheral frictional sur-' faces may be designated as peripheral friction wheels and those that have frictional surfaces on their faces or sides may be designated as face friction wheels. The above terms will be hereinafter employed to designate the saidtwo kinds of friction wheels.

Operation: ,The frictional transmission mechanism described is capable of use in quite a number of different ways, but the usual manner of using the same will be substantially as follows :The transmission mechanism will be thrown into-action by pressing the face friction wheel 8 against the friction rings 23 of the peripheral friction wheels 22. This will simultaneously drive the two shafts 16 at the same speed but in opposite directions, but the two sprockets 33 and 36 will, nevertheless, be driven in the same direction and at the same speed because themo'tion of one shaft- 16 is reversed by the gear 35.- In thus starting, there will be sufficient slippage between the friction wheels 8 and" 22 to prevent shocks, and this is especially so if; the pressure be gradually applied to the said wheel 8; \Vhen this frictional connection ismade between the said wheels, the frictional driving force will be divided between the twowheels 22 and the pressure on the facefri'ct'IOII Wl'IGGl 8 will be equalized on opposite sides of the axis thereof, and hence, there will be no-tendency to bend the driving shaftfor to cramp the same in its bearing,

but on the contrary-, the pressure required to maintain thefrictionalgengagement Will be taken directly in line with the axis of the said driving shaft. These features are highly important. In starting under heavy load or up hill grade, it is advisable to move the sliding peripheral friction wheel 10 forward close to the rim of the face friction wheels 15. When the said face friction wheels 15 are then simultaneously pressed against the friction ring 14 of the said wheel 10, the shafts 16 will be simultaneously driven at the same speed, in reverse directions and at a speed which is considerably slower than that which is produced by engagement of thewheel 8 with the Wheels 22 This gives slow speed and greater power in starting. When the machine" is thus started, the speed may be increased by moving the wheel 10 on the driving shaft 2 toward the axis of the shaft-16. When the friction wheel 10 is set about midway between the axis of the periphery of the friction wheels-15, the driving speed,will be approximately the same as when the friction wheel 8 is engaged with the friction wheels 22, and hence, the shift from the one .set of friction .wheels to the other, may be made without change of speed at such times. When a very high speed is desired, as for/ racing purposes; the friction wheel .10 will be set-quite close 'to the axes of theshafts 16. I When the machine is to be reversedor dni'venbackward and friction wheel 10 is moved to the opposite or rear side f-the axis of the shaft 16, the wheels 15 are then- ,engaged with the said, wheel 10. This aff fords a IGVBISlblQ'fIlOtlOIl drive-that is variable in speed both for driving the-ma-f chine forward and backward. For ordinary 'road speeds, the best results are obtained by theuse of the friction wheels .8 and; 22,

but for the variable transmission of the.

driving power, the adjustable wheel 10, in

coiiperation with the wheels 15, are required. It is, of course, important thatthe variable speed frictional transmission gears be arranged to drive at both higher and lower speeds than the constant speed trans-- missiongears, to-wit the gears 8 and 22.

This moves the greater range of driving actions and permits the driving force to be shifted from the one to the other set of frictional driving gears without change of speed and without shock.

As already stated, sprocket chains, not

shown, will run over the sprockets 33 and 36 and over sprockets of the rear Wheels.

The above described frictional transmission mechanisinprovides for all the various different speeds and other action required for the transmission mechanism of an automobile or motor propelled vehicle.

It is-adapted for use in connection with a steam engine, an explosive engine, and an electric motor. When this frictional transmission mechanism is employed, it performs all of the functions of a variable speed transmission mechanism, of a' reversing device, clutch mechanism, and of a differential or compensating gear,'and its use therefore not only very greatly lightens 'the machine but very "cost' thereof. The-efficiency ofthe transmission mechanism has\ been thoroughly greatly reduces the demonstrated in practice.

What I claim is: 4 1. In a frictional transmission mechanism, the combination with driving and driven shafts, of a face friction wheel and a peripheral friction wheel carriedby said driving shaft, a pair of driven shafts, peripheral friction wheels on said driven shafts for coiiperating with the face frietional wheel on saiddriving shaft, face friction wheels on said driven shafts for cooperation with the peripheral friction wheel on said driving shaft, and means for rendering either of the friction Wheels on said driving shaft operative, at will.

2. Ina frictionaltransmission mechanism, the combination with driving and driven shafts, of a face frictionwheel and a peripheral friction wheelcarried by said driving shaft, said latter wheel being slidably, adjustable thereon, a pair of driven shafts, peripheral friction wheels on said driven shafts for coiiperation with the face friction wheel on said driving shaft, face friction wheels on said driven shafts for cooperation with the said slidably movable friction wheel of said driving shaft, and

means for slidably moving said adjustable driven shafts for cooperation with the face friction wheel on said driving shaft, face friction wheels on said driven shafts for, cooperation with the said slidably movable friction wheel of said driving shaft, means for slidably moving said adjustable friction wheel toward and from the axis of said driven shafts,- means for. engaging either of the two sets of friction wheels, at will, 'a sprocket carried by one of said driven shafts, a gear carried on the other driven shaft, a second gear meshing with the first noted gear,

and a sprocket carried by said second gear, the said two sprockets being driven in the same direction. W

4. In a frictional transmission mechanism, the combination with driving and driven shafts, of a face friction wheel and a peripheral friction wheel carried by said driving shaft, said latter wheel being slidably adjustable thereon, a pair of driven shafts, peripheral friction wheels-on said driven shafts for cooperation with the face friction wheel on said driving shaft, face friction wheels on said driven shafts forcooperation with the said slidably movable friction wheel of said driving shaft, means for 'slidably inovingsaid adjustable fric-.

tion wheel toward and from the axis of said driven shafts, means for engaging either of the two sets of friction wheels, at will, endwise movable thrust bearings in which said driving and driven shafts are ournaled, and

connections for moving-the said thrust bears ings endwise to throw' either of the two sets of friction wheels into action, at will.

- In testimony whereof I aflix my signature in presence of two witnesses.

. BIRGE W. DAVENPORT.

Witnesses:

Bennie-G. WHEELER, HARRY I), KiLoonE. 

